This invention relates to an apparatus for the formation of a stable and uniform selvedge on fabrics which are woven on shuttleless weaving looms. Selvedge forming apparatus of the kind to which this invention refers, are disclosed in my prior U.S. Pat. No. 3,811,479, filed June 12, 1972, having as title "Selvedge forming apparatus in shuttleless looms", to which reference is made for a more complete description of the mode of operation of the said apparatus. The apparatus according to this invention is described as used on a loom of the kind disclosed in my co-pending application Ser. No. 519,172 filed Oct. 30, 1974 and having as title "Method of weaving on shuttleless looms, and loom for performing said method".
In my U.S. Pat. No. 3,181,479 a selvedge-forming device for shuttleless weaving looms is disclosed, comprising a selvedge-forming needle fixedly mounted in a substantially radial position on a needle carrying pivot arranged transversally to the warp threads and rotatably mounted in a selvedge forming head that is slidably guided by the side of the warp threads, and is so reciprocated as to be driven forward, in the direction of the weft inserter path, and backwards, synchronously with the movement of the weft inserter itself. During the said movement of the selvedge forming head, the needle carrying pivot is caused to revolve in one direction so as to angularly lift up the selvedge forming needle in correspondence with a terminal fraction of the forward stroke of the selvedge forming head and turn in the opposite direction so as to angularly lower down the selvedge forming needle at the end of the forward run of the selvedge forming head. According to said my prior patent, the control of the rotational movement of the needle carrying pivot is obtained through a detent into engagement with a lever arm carried by the needle pivot, which detent is caused to be disengaged from said lever arm through a control derived from the rear end of the weft inserter by means of a movable abutment member and a transmission secured to the loom frame.
The above control arrangement was incumbrant, costly and the said transmission was easily damaged.